EP2432079B1

EP2432079B1 - Terminal fitting, female terminal fitting and method of establishing an electric contact of a terminal fitting

Info

Publication number: EP2432079B1
Application number: EP11009725.0A
Authority: EP
Inventors: Keiichi Nakamura; Ryotaro Ishikawa; Song Zheng
Original assignee: Sumitomo Wiring Systems Ltd
Current assignee: Sumitomo Wiring Systems Ltd
Priority date: 2009-12-02
Filing date: 2010-11-10
Publication date: 2014-12-24
Anticipated expiration: 2030-11-10
Also published as: CN102148449B; US8206187B2; EP2432079A1; JP5375564B2; US20110130051A1; EP2330691A1; CN102148449A; JP2011119109A; US20120108114A1; US8152576B2

Description

The present invention relates to a terminal fitting, to a female terminal fitting and to a method of establishing an electric contact of a terminal fitting.
Japanese Unexamined Patent Publication No. 2003-346958 discloses a conventional terminal fitting. This terminal fitting is composed of a female terminal including a main portion in the form of a rectangular tube and a male terminal including a tab. A resilient contact piece is resiliently deformably formed in the main portion. A contact portion is formed to project from the resilient contact piece. When being inserted into the main portion, the tab is resiliently tightly held between the contact portion of the resilient contact piece and an inner surface of the main portion, whereby both male and female terminals are electrically connected.
In the case of the above conventional terminal fitting, when being inserted into the main portion, the tab comes into contact with the contact portion to increase its insertion resistance at once. Thus, operability at the time of terminal connection may be deteriorated.
EP 1 184 941 A1 discloses a terminal fitting, wherein a main body in the form of a rectangular tube having a vertically long cross section, an elastic contact piece formed by folding back an extending part of a left vertical wall and an accommodation space for accommodating a male terminal fitting is defined obliquely upward from the elastic contact piece to the right. When the male terminal fitting inserted into the accommodation space is relatively displaced with respect to a female terminal fitting in a direction normal to longitudinal direction, the male terminal fitting is brought into contact with a contact portion while elastically deforming the elastic contact piece. A pair of restricting projections projecting from upper and lower ends of the elastic contact piece are held in contact with a receiving portion formed to bulge out from the vertical wall, thereby enlarging a contact area of the elastic contact piece with the receiving portion wider than the width of the elastic contact piece. This prevents the elastic contact piece from being twistingly deformed about its longitudinal axis as the male terminal fitting is brought into contact. The contact of the lower restricting projection with a lower horizontal wall prevents the elastic contact piece from being bendingly deformed such that its longitudinal axis is shaken in widthwise direction.
EP 0 657 961 A2 discloses a male terminal fitting wherein a projected portion extending in a lengthwise direction of a tab portion and having a given width is formed in the middle of one laver of the tab portion where there is no seam before the tab portion is formed by folding back the metal plate. The tab portion is allowed to have a specified thickness by the presence of the projected portion. The tab portion thus formed enables the fabrication of a more light-weight male terminal fitting at reduced costs and an increase in its strength.
EP 0 693 798 A1 discloses a male terminal metal fixture having a tab with a standard thickness, although the fixture comprises a thin mother metal plate. The metal fixture is provided with a tab portion which is folded so that each of longitudinal side edges is opposed to each other. The tab portion is provided with an outwardly bulged area with a certain width on the rear side along the opposed longitudinal side edges by means of a bulged process simultaneously with a bending process. Thus, the tab portion can obtain a standard thickness. Moreover, the tab portion is provided with an inward support projection on the outwardly bulged area. The projection prevents the tab portion from being deformed at a hollow space defined by folded side edges and the bulged area.
The present invention was developed in view of the above situation and an object thereof is to improve operability at the time of terminal connection.
This object is solved according to the invention by the features of the independent claims. Preferred embodiments of the invention are subject of the dependent claims.
According to the invention, there is provided a terminal fitting, comprising:

a female terminal including a substantially tubular main portion, and
a male terminal including a tab having a substantially flat shape extending in forward and backward directions to be at least partly inserted into the main portion, wherein the outer circumferential surface of a leading end side of the tab is cut or hammered to form a tapered guidind surface,
a resiliently deformable resilient contact piece being formed in or at the main portion, and both male and female terminals being electrically connected by the contact of the tab at least partly inserted into the main portion with a contact portion of the resilient contact piece,
wherein:
- an outer surface of the tab is formed with a guiding portion for guiding the tab inserted into the main portion to a position where the tab comes into contact with the contact portion,
- the guiding portion is inclined with respect to an inserting direction of the tab and formed from a position before a contact position of the tab with the contact portion at least to the contact position, and
- an inclined projection is formed on the outer circumferential surface of a leading end side of the tab, wherein the upper surface of the inclined projection serves as the guiding portion gradually inclined upward from an end point of the guiding surface toward a back side.

When being inserted into the main portion, the tab is guided by the guiding portion to reach the contact position with the contact portion. Thus, there is no likelihood that the tab suddenly comes into contact with the contact portion to increase insertion resistance at once. Therefore, operability upon connecting both male and female terminals is improved.
According to a preferred embodiment of the invention, a receiving portion for tightly holding the tab at least partly inserted into the main portion between the contact portion and itself is formed to project from the inner surface of the main portion.
Since the guiding portion is formed on the outer surface of the tab, the guiding portion can be deleted from the inner surface of the main portion. Therefore, the construction of the female terminal can be simplified.
Preferably, the guiding portion is so formed that the guiding portion and both an inner surface of the receiving portion and the outer surface of the tab are substantially slidable on each other.
Since the guiding portion is so formed that the guiding portion and both the inner surface of the receiving portion and the outer surface of the tab are substantially slidable on each other, a contact load accompanying the contact of the tab and the contact portion can be increased by a smaller degree, wherefore operability is further improved.
These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments.

FIG. 1 is a section showing a state before a tab is inserted into a main portion in a terminal fitting according to a first embodiment not covered by the scope of the claims,
FIG. 2 is a section showing a state during insertion of the tab into the main portion,
FIG. 3 is a section showing a state where the tab is inserted in the main portion,
FIG. 4 is a front view of a female terminal,
FIG. 5 is a section showing a state before a tab is inserted into a main portion in a terminal fitting according to a second embodiment not covered by the scope of the claims,
FIG. 6 is a front view showing a state where the tab is inserted in the main portion,
FIG. 7 is a front view of a female terminal in a terminal fitting according to a third embodiment not covered by the scope of the claims,
FIG. 8 is a section showing a state before a tab is inserted into a main portion in a terminal fitting according to a fourth embodiment which corresponds to the embodiment of the present invention,
FIG. 9 is a section showing a state during insertion of a tab into a main portion in a terminal fitting according to a fifth embodiment not covered by the scope of the claims,
FIG. 10 is a section showing a state before a tab is inserted into a main portion in a terminal fitting according to a sixth embodiment not covered by the scope of the claims, and
FIG. 11 is a front view of a female terminal.

A first embodiment not covered by the scope of the claims is described with reference to FIGS. 1 to 4. A terminal fitting according to the first embodiment is composed of at least one pair of female and male terminals 10, 50 connectable with each other. Both terminals 10, 50 are formed particularly by applying bending and the like to an electrically conductive (particularly metal) plate.
The male terminal 50 includes a tab 51. The tab 51 has a substantially flat shape extending in forward and backward directions (longitudinal direction). The outer circumferential surface of a leading end side of the tab 51 particularly is cut or hammered to form a tapered guiding surface 52.
The female terminal 10 includes a tubular main portion 11. A wire connection portion (particularly comprising an unillustrated crimping portion) is formed behind the main portion 11. The wire connection portion is connectable to an unillustrated wire particularly in that the crimping portion is crimped and connected to an end portion of an unillustrated wire.
The main portion 11 particularly is in the form of a substantially rectangular tube and includes a base plate 12 continuous with the wire connection portion (particularly the crimping portion), a pair of side plates 13 standing up from the opposite widthwise ends of the base plate 12 and a ceiling plate 14 bridging the upper ends of one and the other side plates 13. A resilient contact piece 15 is formed in or at the main portion 11. The resilient contact piece 15 particularly is formed to have a substantially mountain shape by folding a part projecting forward from the front end of the base plate 12 backward. A top portion of the resilient contact piece 15 particularly is hammered to form a rounded or substantially semispherical contact portion 16 projecting upward or inward. Such a resilient contact piece 15 is resiliently deformable in a direction intersecting a tab insertion direction ID (particularly substantially upward and downward) with its part continuous with the front end of the base plate 12 as a supporting point.
The ceiling plate 14 is formed with a receiving portion 17 at a position substantially facing the resilient contact piece 15 in a resiliently deforming direction of the resilient contact piece 15. The receiving portion 17 particularly is formed by hammering a widthwise intermediate or central part of the ceiling plate 14 to project inwardly and/or substantially in the form of a rib extending in forward and backward directions, and/or has a trapezoidal cross section. An inner surface of the receiving portion 17 particularly substantially is even and wide in its entirety. Further, the inner surface of the receiving portion 17 is formed with a guiding portion 18 inclined to gradually approach the resilient contact piece 15 from its front end toward its back side. A starting point of the inclination of the guiding portion 18 particularly is located between the front end of the resilient contact piece 15 and the contact portion 16, and an end point of the inclination of the guiding portion 18 is located between the contact portion 16 and the rear end of the resilient contact piece 15. In other words, the contact portion 16 is arranged to substantially face an intermediate position of the guiding portion 18. Thus, the guiding portion 18 is formed with such a length range from a position before a contact position of the tab 51 with the contact portion 16 to the contact position.
A vertical distance between the end point of the inclination of the guiding portion 18 and the top of the contact portion 16 when the resilient contact piece 15 is in its natural state is set to be smaller than the thickness of the tab 51. Further, the inner surface of the receiving portion 17 particularly is formed with a substantially horizontal and/or wide flat surface 19 from the end point of the inclination of the guiding portion 18 to the rear end of the receiving portion 17.
The terminal fitting according to this embodiment is structured as above. Next, how to connect the terminal fitting is described.
First of all, the male terminal 50 is at least partly accommodated in an unillustrated male connector housing and the female terminal 10 is also at least partly accommodated in an unillustrated female connector housing. Subsequently, the two connector housings are connected with each other. Then, the tab 51 is at least partly inserted into the main portion 11 in the tab insertion direction ID e.g. from front. As shown in FIG. 2, in an insertion process, the tab 51 comes into contact with the guiding portion 18 before coming into contact with the contact portion 16 and is or may be displaced in a direction intersecting with the tab insertion direction ID or little by little toward the contact portion 16 while substantially sliding on the guiding portion 18. Subsequently, the tab 51 comes into contact with the contact portion 16 from above to resiliently deform the resilient contact piece 15 substantially outward or downward. Also during resilient deformation of the resilient contact piece 15, the tab 51 keeps substantially sliding on the guiding portion 18. When a leading end portion of the tab 51 reaches a position to be held in contact with the flat surface 19 as shown in FIG. 3 in this way, the tab 51 is resiliently tightly held between the receiving portion 17 and the resilient contact piece 15, with the result that both female and male terminals 10, 50 are electrically connected.
As described above, according to this embodiment, the tab 51 is guided by the guiding portion 18 and reaches the position to be held in contact with the contact portion 16 when being at least partly inserted into the main portion 11. Thus, as compared with the case where the tab 51 suddenly comes into contact with the contact portion 16, a sudden increase in insertion resistance can be prevented. In this case, since the contact portion 16 is arranged to substantially face the intermediate position of the guiding portion 18, a guiding function by the guiding portion 18 can be displayed with the tab 51 held in contact with the contact portion 16. Therefore, insertion resistance accompanying the contact of the tab 51 and the contact portion 16 can be gradually increased, wherefore operability upon bringing both female and male terminals 10, 50 into contact is improved.
Since the guiding portion 18 particularly is formed on the inner surface of the receiving portion 17 of the main portion 11, the receiving portion 17 can have both a function of holding the tab 51 between the resilient contact piece 15 and itself and a function of guiding the tab 51. As a result, the construction of the main portion 11 can be simplified.
Accordingly, to improve operability at the time of terminal connection, a tab 51 of a male terminal 50 is to be at least partly inserted into a main portion 11 of a female terminal 10. The tab 51 comes substantially into contact with a contact portion 16 of a resilient contact piece 15, whereby both female and male terminals 10, 50 are electrically connected. A guiding portion 18 for guiding the tab 51 at least partly inserted into this main portion 11 to a position where the tab 51 comes into contact with the contact portion 16 is formed on an inner surface of the main portion 11. The guiding portion 18 is formed from a position before a contact position of the tab 51 with the contact portion 16 to the contact position while being inclined with respect to an inserting direction ID of the tab 51.

FIGS. 5 and 6 show a second embodiment not covered by the scope of the claims. In this female terminal 10, a widthwise intermediate or central part of a ceiling plate 14 of a main portion 11 is hammered or deformed to substantially project inward or downward, thereby forming a narrow receiving portion 17A. This receiving portion 17A particularly has a substantially V- or U-shaped cross section. A top portion of the receiving portion 17A serves as a guiding portion 18A inclined to gradually approach a resilient contact piece 15 from its front end toward its rear end. The other construction is substantially similar to or same as that of the first embodiment.
In the process of inserting a tab 51 into the main portion 11, the tab 51 is guided toward or to a contact position with a contact portion 16 by the guiding portion 18A. When being inserted to a proper depth in the main portion 11, the tab 51 is tightly held between the guiding portion 18A and the contact portion 16 while being supported at two points. In this way, both terminals 10, 50 are electrically connected. According to such a second embodiment, the effects described in the above first embodiment can be enjoyed.

FIG. 7 shows a third embodiment not covered by the scope of the claims. In this female terminal 10, opposite widthwise sides of a ceiling plate 14 of a main portion 11 are hammered or deformed to substantially project inward or downward, thereby forming a pair of substantially narrow receiving portions 178. In other words, the pair of receiving portions 17B overall have a substantially W-shape. Each receiving portion 17B has a substantially U-shaped cross section. A top or distal portion of each receiving portion 17B serves as a guiding portion 18B inclined to gradually approach a resilient contact piece 15 from its front end toward its rear end. The other construction is substantially similar to or same as that of the first embodiment.
In the process of inserting a tab 51 into the main portion 11, the tab 51 is guided to a contact position with a contact portion 16 by the respective guiding portions 18B. When being inserted to a proper depth in the main portion 11, the tab 51 is tightly held between the respective guiding portions 18B and the contact portion 16 while being supported at three points. In this way, both terminals 10, 50 are electrically connected. According to such a third embodiment, the effects described in the above first embodiment can be enjoyed.

FIG. 8 shows a fourth embodiment which corresponds to the embodiment of the present invention. A receiving portion 17C formed at a ceiling plate 14 of this female terminal 10 is formed with no guiding portion. Specifically, not a guiding portion, but a substantially flat surface 19C is formed at a position of the receiving portion 17C substantially facing a contact portion 16. An inclined portion 21 shorter than the guiding portion 18 in forward and backward directions is formed at a front end portion of the receiving portion 17C. The other construction of the female terminal 10 is substantially similar to or same as that of the first embodiment.
On the other hand, an inclined projection 53 is formed on the outer circumferential surface of a leading end side of a tab 51. The upper surface of the inclined projection 53 serves as a guiding portion 54 gradually inclined upward or outward from an end point of a guiding surface 52 toward a back side. The guiding portion 54 particularly substantially is even and/or wide. Such a guiding portion 54 is also formed from a position before a contact position of the tab 51 with a contact portion 16 to the contact position with the contact portion 16.
In the process of inserting the tab 51 into a main portion 11, the guiding portion 54 slides on the inclined portion 21 of the receiving portion 17C and the tab 51 is displaced toward a resilient contact piece 15. While the guiding portion 18 substantially is sliding on the inclined portion 21 of the receiving portion 17C, the tab 51 comes into contact with the contact portion 16 from above to resiliently deform the resilient contact piece 15 in a direction intersecting with the tab inserting direction ID or substantially downward. When being inserted to a proper depth in the main portion 11, the tab 51 is resiliently tightly held between the flat surface 19C of the receiving portion 17C and the contact portion 16, whereby both terminals 10, 50 are electrically connected.
According to the fourth embodiment, the guiding portion can be deleted from the female terminal 10 and the construction of the female terminal 10 can be simplified since the guiding portion 54 is formed on the outer circumferential surface of the tab 51.

FIG. 9 shows a fifth embodiment not covered by the scope of the claims. In this female terminal 10, a part of a ceiling plate 14 is cut and bent into a main portion 11, thereby forming a receiving portion 17D. An inner surface of the receiving portion 17D is formed with a guiding portion 18D gradually inclined toward a resilient contact piece 15 from its front end toward its rear side and a substantially horizontal flat surface 19D from an end point of the inclination of the guiding portion 18D to the rear end of the receiving portion 17D. Further, a part of the ceiling plate 14 before the receiving portion 17 is hammered or deformed to substantially project inward or downward, thereby forming a front receiving portion 22. A substantially horizontal and/or wide supporting surface 23 particularly is formed on an inner surface of the front receiving portion 22. The other construction is substantially similar to or same as that of the first embodiment.
In the process of inserting the tab 51 into the main portion 11, the upper surface of the tab 51 slides on the supporting surface 23 of the front receiving portion 22 and the leading end of the tab 51 slides on the guiding portion 18D, whereby the tab 51 is substantially displaced toward the contact portion 16. While the leading end of the tab 51 substantially is sliding on the guiding portion 18D, the resilient contact piece 15 is resiliently pushed down by the tab 51 to increase insertion resistance gradually or little by little. When being inserted to a proper depth in the main portion 11, the tab 51 is resiliently tightly held between the flat surface 19D of the receiving portion 17D and the contact portion 16, whereby both terminals 10, 50 are electrically connected.
According to the fifth embodiment, since the guiding portion 18D is formed on the inner surface of the receiving portion 17D particularly formed by cutting the part of the ceiling plate 14 of the main portion 11 and bending this cut part toward the contact portion 16, a degree of freedom in the form of the guiding portion 18D can be increased as compared with the case where the guiding portion is formed by hammering the ceiling plate 14 to project toward the contact portion 16.

FIGS. 10 and 11 show a sixth embodiment not covered by the scope of the claims. This differs from the terminal fitting of the first embodiment in its basic structure. A main portion 11 E of a female terminal 10E has an upper portion (preferably substantially an upper half) thereof closed by a closing wall 24 hanging down or inwardly or projecting from the front end of a ceiling plate 14E, and an insertion opening 25 for a tab 51 E is formed in a lower portion (preferably substantially in a lower half). At least one stabilizer 25 is formed to stand up from the upper end of a side plate 13E particularly by cutting and bending a part of the ceiling plate 14E. A resiliently deformable resilient contact piece 15E is formed in or at or on the main portion 11 E. The resilient contact piece 15E particularly is formed by folding a part extending backward from the rear end of the ceiling plate 14E forward and closely bending the forward extending part at a position facing the insertion opening 25 such that the leading end thereof extends up to the inner surface of the ceiling plate 14E. A contact portion 16E is formed to project at a bottom end of a closely bent part of the resilient contact piece 15E.
Substantially opposite widthwise end portions of a bottom plate 12E are hammered or deformed to project inward or upward, thereby forming a pair of receiving portions 17E. First guiding portions 18E inclined to gradually approach the resilient contact piece 15E from the front end of the bottom plate 12E toward a rear side thereof are formed on inner surfaces of the respective receiving portions 17E. The respective receiving portions 17E are arranged at the substantially opposite sides of the contact portion 16E with respect to a width direction as shown in FIG. 11.
On the other hand, the outer circumferential surface of the tab 51 E are cut at substantially opposite widthwise sides thereof, thereby forming a pair of second guiding portions 54E gradually sloped downward from the leading ends thereof toward rear sides thereof. The respective second guiding portions 54E are in such a positional relationship as to at least partly overlap a guiding surface 52E formed on the outer circumferential surface of a leading end side of the tab 51 E.
In the process of at least partly inserting the tab 51 E into the main portion 11E, the respective second guiding portions 54E slide on the corresponding first guiding portions 18E to gradually displace the tab 51 E substantially toward the contact portion 16E. When the tab 51 E comes into contact with the contact portion 16E laterally or from below, the resilient contact piece 15E is resiliently deformed outward or upward. Also during this time, a sliding contact state of the first and second guiding portions 18E, 54 is maintained to increase insertion resistance of the tab 51 E gradually or little by little. When being inserted to a proper depth in the main portion 11 E, the tab 51 E is tightly held between the receiving portions 17E and the contact portion 16E, whereby both terminals 10E, 50E are electrically connected.
According to the sixth embodiment, a contact load accompanying the contact of the tab 51 E and the contact portion 16E can be increased by a smaller degree, wherefore operability is further improved.

LIST OF REFERENCE NUMERALS

10, 10E: female terminal
11, 11 E: main portion
12: base plate
13: side plates
14, 14E: ceiling plate (one wall)
15, 15E: resilient contact piece
16, 16E: contact portion
17, 17A, 17B, 17C, 17D, 17E: receiving portion
18, 18A, 18B, 18D, 54: guiding portion
18E: first guiding portion (guiding portion)
19, 19C, 19D: flat surface
21: inclined surface
22: front receiving portion
23: supporting surface
24: closing wall
25: insertion opening
50, 50E: male terminal
51, 51E: tab
52: guiding surface
53: inclined projection
54E: second guiding portion (guiding portion)
ID: inserting direction

Claims

A terminal fitting, comprising:
a female terminal (10) including a substantially tubular main portion (11), and

a male terminal (50) including a tab (51) having a substantially flat shape extending in forward and backward directions to be at least partly inserted into the main portion (11), wherein the outer circumferential surface of a leading end side of the tab (51) is cut or hammered to form a tapered guiding surface (52),

a resiliently deformable resilient contact piece (15) being formed in or at the main portion (11), and both male and female terminals (10, 50) being electrically connected by the contact of the tab (51) at least partly inserted into the main portion (11) with a contact portion (16) of the resilient contact piece (15),

wherein:
an outer surface of the tab (51) is formed with at least one guiding portion (54) for guiding the tab (51) inserted into the main portion (11) to a position where the tab (51) comes into contact with the contact portion (16),

characterised in that:
the guiding portion (54) is inclined with respect to an inserting direction (ID) of the tab (51) and formed from a position before a contact position of the tab (51) with the contact portion (16) at least to the contact position, and

an inclined projection (53) is formed on the outer circumferential surface of a leading end side of the tab (51), wherein the upper surface of the inclined projection (53) serves as the guiding portion (54) gradually inclined upward from an end point of the guiding surface (52) toward a back side.
A terminal fitting according to claim 1, wherein:
a receiving portion (17C) for tightly holding the tab (51) at least partly inserted into the main portion (11) between the contact portion (16) and itself is formed to project from the inner surface of the main portion (11).
A terminal fitting according to claim 1 or 2, wherein the guiding portion (54) substantially is even and/or wide.
A terminal fitting according to any one of claims 1 to 3, wherein a flat surface (19C) is formed at a position of the receiving portion (17C) substantially facing the contact portion (16).
A terminal fitting according to any one of claims 1 to 4, wherein an inclined portion (21) is formed at a front end portion of the receiving portion (17C).